Interesting that he identifies three things and then comments on the two which really ARE obviously true long term and not on the third which is much more debatable.
When I go to Amazon I'd often prefer a smaller selection of items for common categories, with better price/quality tradeoff information, and an assurance that I wasn't going to get an inferior substitute.
Not that it's an EASY problem to solve, particularly at Amazon's scale, but it's also the thing where it's most likely that a customer will come up and say "Jeff, I just want to be able to order a USB key that has the capacity it claims without having to wade through thousands of shady vendors".